XCopyArea clip bug

[Alexander Larsson]

On Wed, 2009-02-04 at 13:38 +0100, Alexander Larsson wrote:
> I found what I think is a bug in XCopyArea. 
> 
> If you copy a pixmap to a window and some of the copied area is outside
> the pixmap then that area in the destination window is cleared to the
> background color (and possibly graphics exposes are sent).
> 
> If the GC has a clip region set so that the destination area that would
> contain data from outside the pixmap is clipped out, then I would expect
> it to not be cleared. 
> 
> However, that is not the case right now, even the clipped out area has
> the destination cleared to the window background.
> 
> I'm attaching an xlib example.

Oh, the same thing happens if the source is another window and not a
pixmap.